So at last, and after only seven requests, we have some references. And, to no gasps of surprise, they reveal that the “papers” on which Alexander Cockburn bases his claim that carbon dioxide doesn’t cause global warming have not been published in peer-reviewed scientific journals. In fact they have not been published at all.

Cockburn appears not to understand the implications of this. Aware that I might as well argue with a tree stump, let me explain – again and for the last time – what it means. If these papers have not been published in peer-reviewed scientific journals, they are not science. They carry no more scientific weight than an article in the National Enquirer.

The man who wrote them, Martin Hertzberg, has kindly sent me copies. The howling scientific errors Cockburn makes do indeed stem from this work. (They are demolished here: http://www.realclimate.org/index.php/archives/2007/05/this-week/). This is why the peer-review process exists: to weed out nonsense. Hertzberg informs me that he has tried to get his “papers” published in scientific journals, but he has failed: his nonsense has been weeded out. It is our misfortune that Alexander Cockburn does not understand this.

But Cockburn will heed no warnings, listen to no one with whom he disagrees. In my last posting, I gave an example of straightforward scientific fraud perpetrated by Patrick Michaels. Cockburn now tells us that “I haven’t seen any significant dents or quantitative ripostes to his meticulous scientific critiques.” Well, it’s time he started looking.

But there is no elephant trap he is incapable of falling into. He now cites a “paper” by Professor Zbigniew Jaworowski, published in 21st century Science and Technology. It sounds impressive, doesn’t it? But the briefest check would have established that this is not only not a scientific journal, it is in fact an anti-scientific journal. It is owned and published by Lyndon Larouche. Larouche is the ultra-rightwing US demagogue who in 1989 received a 15-year sentence for conspiracy, mail fraud and tax code violations. He has claimed that the British royal family is running an international drugs syndicate, that Henry Kissinger is a communist agent and that the British government is controlled by Jewish bankers. He sees science and empiricism as yet another conspiracy, and uses 21st Century Science and Technology to wage war against them.

Cockburn is not the only one to have fallen for this impressive title: it was also the undoing of the former British environmentalist David Bellamy (as you can see here: http://www.monbiot.com/archives/2005/05/10/junk-science/). But Bellamy is notorious for failing to conduct research before opening his mouth. Should the same now be said of Cockburn? Did he bother to check this source before citing it? Has he checked any of his sources?

The answer is plainly no. He has waded unprepared into this debate and as his errors are exposed, he lashes out with ever wilder accusations and conspiracy theories. In his attack on the 9/11 truth movement, he rightly complains that “the “conspiracy” is always open-ended as to the number of conspirators, widening steadily to include all the people involved in the execution and cover-up â€¦. “. Now he invokes a conspiracy that widens steadily to include thousands of climate scientists: “the beneficiaries of the $2 billion-a-year global warming grant industry”. Even the most cursory research would have shown that climate scientists have been consistently punished by the grant-givers in the Bush government for speaking out on global warming and rewarded for hushing it up – you can read more here: http://www.monbiot.com/archives/2007/04/10/the-real-climate-censorship/. Should anyone be surprised by this? Or is Bush now part of the conspiracy too?

I have now learnt that it is pointless to seek to argue with Cockburn. Because he cannot admit that he got the science wrong, he merely raises the volume and widens the scope of his attack. Resorting to grapeshot, he now invokes just about every crazy theory ever raised by those who say that manmade global warming is not happening. It would require an entire website to answer them all. Happily, it already exists – www.realclimate.org – and, over the years, it has dealt with every new issue he raises, drawing on peer-reviewed papers. But Cockburn will not read these refutations. He has answered none of his critics; he has not even listened to them. For this reason, this will be my last posting in this debate.

I sign off with sadness. I have followed Alexander Cockburn’s writing for many years and I have admired it. His has been an important and persuasive voice on many progressive issues. But I can no longer trust it. I realise that he is blinded by a conviction that he remains right whatever the facts might say. In his determination to admit nothing, he will cling to any straw, including the craziest fulminations of the ultra-right, and he will abandon the rigor and scepticism that once informed his journalism. I feel this as a loss. I am sure I am not the only one.